I have a similar opinion of Claude Sonnet. Superhuman knowledge; ability to apply it to solve new math/coding problems at roughly the level of a motivated high-schooler (but not corresponding exactly in profile to anything human); less ability to stay on track the longer the effort takes.

But ChatGPT a couple years ago was at more like grade-school level at problem-solving. What should I call this thing that the best LLMs can do better than the older ones, if it's not actual reasoning? Sparkling syllogistics?

Sorry, that's sarcastic, but... it's from a real exasperation at what seems like a rearguard fight against an inconvenient conclusion. I don't like it either! I think the rate of progress at building machines we don't understand is dangerous. (Understanding the training is not understanding the machinery that comes out.)

Compare the first previews of Copilot with current frontier "reasoning" models, and ask how this will develop in the next five years. Maybe it'll fizzle. If you're very confident it will: I'd like to be convinced too.